Perkin-Elmer Computerized Microdensitometer (PDS)

Year: 197?
Manufacturer: Perkin Elmer Corp. (US)
Materials: cast iron, steel, brass, optical glass
Dimensions: L = 2000 mm; P = 2000 mm; H = 2300 mm

Made in the 1970s by Perkin-Elmer Corp. in the United States, this computerized microdensitometer represents an evolution in measuring the optical density of photographic plates. With a spatial resolution of 1 micron and an analysis speed of about 200 mm per second, the instrument offered superior precision and speed compared to previous devices.

The operating principle is simple but effective: a light beam of known intensity passes through the plate at a specific point, and the photoelectric tube measures the transmitted light, proportional to the degree of blackening. This system allowed surface brightness analysis of extended objects and spectrophotometric measurements with great accuracy, making it a key instrument for astrophotography and spectroscopy.